Exhaust-gas mufflers of this kind are, for example, of motor-driven chain saws, suction/blower apparatus, brushcutters or the like and are flange connected directly to the cylinder of. the engine. A muffler housing of the exhaust-gas muffler has attachment means, especially, in the form of flange screws which are provided on the engine-end wall of the muffler housing. The attachment means are in the immediate proximity of an inlet window through which the hot exhaust gases of the engine flow into the interior of the exhaust-gas muffler. The hot and pulsating exhaust-gas flow generates considerable thermal and mechanically vibrating loads in the attachment means and especially in the engine-end wall of the muffler housing.
Overall, a low weight is sought for a good manipulability of the work apparatus. With a view to a low overall weight, the walls of the muffler housing are designed to be thin. A low muffler weight leads especially to a mechanical loading of the attachment means and the engine-end wall under vibration load. A thin-walled design of the engine-end wall is disadvantageous because of the low bending stiffness thereof which permits an elastic deformation transverse to the wall plane. For corresponding thermal and/or mechanical loading, the stress of the engine-end wall because of bending load, curving load and/or torsion load can be disadvantageous.
Exhaust-gas mufflers are known wherein the engine-end wall is provided with a support disc on the inner side of the muffler housing in the region of the attachment means. The support disc is intended to lead to a local reinforcement of the engine-end muffler wall and to a planar introduction of the screw forces. To achieve an adequate reinforcement effect, a corresponding thickness of the support disc is required which operates disadvantageously on the total weight of the exhaust-gas muffler. Stress peaks in the region of the edges of the support discs are avoidable only to a limited extent.